Hypodermic syringe



July 22, 1958 A. RAIFE 2,844,148

HYPODERMIC SYRINGE FiledO ct. 15, 1955 a4 72 IIIY/ZENTOR. BY ZZZ UnitedStates Patent HYPODERMIC SYRINGE Archie Raife, Chicago, Hl. ApplicationOctober 13, 1955, Serial No. 540,217

1 Claim. (Cl. 128-218) My invention relates to improvements inhypodermic syringes.

One of the objects of my invention is the provision of an improvedsyringe affording means for rapidly dispensing with a high degree ofaccuracy a plurality of successive doses of medicament or other liquidmedia.

Another object of my invention is the provision of a syringe of theforegoing type having means for arresting the travel of the plunger atpredetermined points so as to permit the dispensing of successivepredetermined quantities of liquid media without requiring the operatorto observe the graduate markings on the barrel of the syringe.

A further object of my invention is the provision of a device of theforegoing character, which is simple in construction, efficient inoperation and durable in service.

Other and further objects and advantages of my invention will becomeapparent from the following description when considered in connectionwith the accompanying drawing, in which:

Fig. 1 is a longitudinal cross-sectional view of a hypodermic syringeembodying my invention;

Fig. 2 is an enlarged elevational view of a portion of the plunger,looking in the direction of the arrows 2-2 of Fig. 1;

Figs. 3, 4 and 5 are cross-sectional views taken, respectively, on line3, 4 and 5 of Fig. 2; and

Fig. 6 is a fragmentary perspective view of a portion of 'the plungerrod.

Referring to the drawings, numeral 10 indicates generally a hypodermictype syringe comprising a tubular frame 11 enclosing a glass barrel 12.The forward end of the frame 11 is inwardly flanged, affording aretaining shoulder 13 for a taplet 14 into which is screwed an adapter16 into which is fitted a hypodermic needle 17. The end of the barrel 12abuts a washer 18 lying adjacent an annular wall of the taplet. Theopposite end of the frame is threaded exteriorly to receive a retainingcap 19, which is centrally threaded to receive a retaining member 21. Amember 22 providing diametrically opposed finger-engaging portions 23 isthreaded on the end portion of the frame 11. The fore going structure isof conventional construction and forms no part of the present invention.

My invention is particularly related to a plunger rod construction,presently to be described. The plunger rod indicated generally by thenumeral 25 is of generally cylindrical construction provided at each endwith a reduced threaded portion. The forward end of said plunger rod isadapted to be received within a plunger or piston 26, which is influid-tight relation with the inner wall of the barrel 12. The oppositeend of the said plunger rod is in threaded engagement with a knob 27. Itwill be understood that the plunger and knob are of conventionalconstruction. A major portion of the plunger rod 25 intermediate theplunger and knob is provided with 2 a longitudinally extending groove28. Spaced from the ends of the plunger rod are front and rear annulargrooves 29 and 30, respectively, the said grooves intersecting thelongitudinal groove 28.

On the surface portion of the plunger rod opposite the groove 28 the rodis provided with a series of flats or flat surfaces, with adjacent flatsdisposed in angularly related planes so that thejunctures of adjacentflats afford shoulders or abutments for a purpose, as will behereinafter described. Specifically, adjacent the forward annular groove29 there is provided a first flat 31 which is substantially tangent tothe bottom of the said groove. A second fiat 32 is disposed adjacentsaid first flat, but occupies a plane in angular relation thereto. Atthe end of flat 31 coinciding with the line of juncture of flats 31 and32 a shoulder 33 is formed providing an abutment or stop. A relativelynarrow auxiliary-flat 34 is provided adjacent thefshoulder 33, the planeof said auxiliary flat being angularly intermediate both said first andsecond flats 31 and '32, respectively, and affording a means ofcrossover between said first and second flats, as will be hereinafterexplained. A third flat 35 is disposed adjacent to the second flat 32but is co-planar with'the first flat 31. A second shoulder 36 is formedat the end of flat 32 coinciding with the line of juncture of the secondand third flats 32 and 34, respectively. The second flat 32 is connectedto the third flat 34 by a relatively narrow auxiliary flat 37 which isco-planar with the auxiliary flat 34 but laterally offset therefrom.Fourth. and fifth flats 38 and 39, respectively, are provided, formingshoulders 41 and 42 the first, third and fifth flats 31,35 and 39,respectively, being co-planar and the second and fourth flats 32 and 38,respectively, being co-planar. Auxiliary flats 43 and 44 similar toauxiliary flats 34 and 37 afford crossover means between flats 35 and 38and flats 38 and 39, respectively. It will be observed that all of theflats are substantially tangent.

In the embodiment illustrated, the distances between shoulders 33, 36,41 and 42 are equal. Accordingly, as will be apparent, the total travelof the plunger rod 25 is divided into five equal increments. It will beunderstood, however, that the invention is not limited to the number offlats shown but may embody a lesser or greater number.

The retaining member 21 is provided with an inwardly directed pin 46which is adapted to engage in the grooves and against the shouldersprovided on the plunger rod, as will be hereinafter explained.

In the operation of the device, when the plunger rod 25 is at theforward limit of its stroke and occupies the position illustrated inFig. 1, the pin 46 is in registration with the rearward annular groove30. Accordingly, the plunger rod may be rotated axially by means of theknob 27 until the longitudinal groove 28 is in registration with the pin46. Filling of the barrel is accomplished in a conventional manner bysubmerging the tip of the needle in a liquid media and withdrawing theplunger rod outwardly in the direction of the dotted line portionillustrated-in Fig. 1. When the plunger rod is in its outermostposition, the pin 46 is in registration with the forward annular groove29 and the plunger rod then may be rocked about its longitudinal axis toalign the first flat 31 with the pin 46. The plunger rod then may bepushed forwardly until the pin 46 engages the first shoulder 33, whichlimits axial movement of the plunger and plunger rod. The amount ofliquid media ejected in the first increment of travel of the plungercorresponds to a predetermined volume of media. In the use of myinvention the operator is not required to observe the liquid levelwithin the barrel in relation to the graduation lines on the barrel. Inorder to dispense the next dosage, the

the barrel with a liquid media.

aligned substantially with the median line of the third fiat 3,5. Forsuccessive dispensing of dosages of liquid media contained Within thebarrel12, the operations heretofore described are repeated until theplunger 26 reaches the end of its stroke and is in substantial abutmentwith the inner face of the t-aplet 14. In this position the pin 46 isaligned with the rearwardannular groove 30, and the plunger rod 25 maybe: rotated axially in order to align the longitudinal channel groove 28with the pin 46,

so that the plunger rod maybe withdrawn to again fill However, it willbe apparent that, while only five abutments or shoulders are illustratedin the drawings, it is contemplated that a greater or smaller number ofsuch abutrnents or shoulders may be provided on the plunger rod.

It will be noted that when the pin 46 is aligned with any of the flatsthe plunger rod may be rocked axially only to a very limited degree,because the pin 46 will be caused to engage the side marginal edgeportions of the main flats. Thus the plunger rod 25 is held to itscourse during each increment of travel, assuring accuracy in thedispensing of a predetermined quantity of liquid media.

It will be apparent from the foregoing that the length of each main fiatmay be varied in order to yield a desired quantity of liquid media. Itwill also be apparent from the foregoing that I have provided animproved syringe which is capable of dispensing a plurality of pre- 4determined quantities of liquid media rapidly in successive order.

Various changes coming within the spirit of my invention may suggestthemselves to those skilled in the art. Hence, I do not wish to belimited to the specific embodiments shown and described or usesmentioned, but intend the same to be merely exemplary, the scope of myinvention being limited only by the appended claim.

I claim:

A syringe type dispenser comprising a barrel, a plunger and plunger rodreciprocable within said barrel, a stationary abutment associated withthe rearward portion of said barrel, said plunger rod having an annularrecess substantially at each end and a longitudinally extending recessconnecting said annular recesses, said plunger rod having intermediatesaid annular recesses and connecting therewith a series oflongitudinally extending recesses of predetermined lengths with adjacentrecesses misaligned to afford a stop at the end of each recess, saidabutment being adapted to be selectively disposed in registration withsaid recesses 'by movement of said plunger rodwhereby when saidlongitudinally extending recess is in registration with said abutmentsaid plunger rod may be moved longitudinally Within the limits definedby said annular recesses, said abutment when disposed in registr-ationwith said series of recesses during the forward travel of said plungerrod being successively engaged by said stops, whereby the movement ofsaid plungerrod is arrested at predetermined increments of travel.

References Cited in the file of this patent UNITED STATES PATENTS Lomaset al. Oct. 11, 1921

